1. Field of the Invention
The instant invention lies generally in the field of tortilla presses, and more specifically deals with actuation means for different parts of the press or for initiating different steps of the process of making tortillas with the press.
2. Disclosure of the Prior Art
The prior art has tortilla presses with actuation means for stopping and starting an endless belt and for lowering and raising a tortilla press. However the prior art is deficient in a variety of ways. Overall, the prior art utilizes old technology and methods that are inadequate with regard to precision, flexibility, and efficiency.
Firstly, the closest prior art presses employ two proximity sensors that work together. The first sensor senses a separate element held in position on the endless belt and sends a signal to the belt drive to stop the belt. The first sensor also sends a signal to a processor. The second sensor senses the separate element a short period of time after the first sensor does and sends a signal to the processor. By use of at least one timer, the processor estimates the needed time for the belt to completely stop and then waits an additional period after that to provide a safety factor before sending a signal to the tortilla press platen actuator to cause the platen to descend and press the tortillas. This arrangement and process of the prior art is costly in time and accuracy.
Secondly, the sensors utilized in the prior art are proximity sensors and the detectable elements utilized by the prior art presses are therefore usually metal strips that have to be adhered to the belt or placed in pockets to hold the metal strips in place on the belt. This arrangement is inadequate because it is inflexible. That is, only a few types of elements will effectuate sensing by the proximity sensor. Also, the attachment is labor intensive and the location of the detectable elements relatively permanent. Thus, the prior art systems and methods are inflexible.
Thirdly, the sensing of the prior art does not utilize direct feedback, but relies on calculations, estimates, and timers. This prior art approach is inadequate because it requires the addition of a safety factor to assure that the belt is stopped before the platen is brought down. Even the calculations and estimates may cause lost time since some cycles or speeds require less time than others. Hence, the prior art is deficient in achieving the greatest possible efficiency.
Fourthly, another way in which the prior art devices are inadequate is in the location of the sensors. The sensors of the prior art have been located at a position along the belt at which the belt has relatively high slack in a direction perpendicular to the direction of travel of the belt. Such a position is likely to give erroneous readings since the detectable element is not constrained to a single path as it passes the sensor. That is, the detectable element may be “bouncing” as it passes the sensor, as well as traveling along with the belt.